U.S. Pat. No. 4,334,467 A shows a round baler of the fixed chamber type with rotatable side walls of the size and shape of a round bale. These side walls are arranged inside of drums, which are journalled and rotate concentrically to the side walls. While the side walls almost slide along the inner side of the drum, endless bale forming elements with chains rest on the outer surface of the drum and move with it over about 270 degrees. The endless bale forming elements are routed over rolls in a gate and are lifted off the drum, as soon as the gate opens. A comparable design is shown in WO 2006/040783.
EP 1 364 574 A discloses a round baler, which can be of the variable or of the fixed chamber type, and which has side walls extending over the side surface of the bale chamber. A gate rotates about the center of the bale chamber and has rolls carrying endless bale forming elements, which move along the circumference of the side walls, when the gate opens. These side walls are moveable to and from the face sides of the bale chamber. When the gate closes, ramps on the gate move the walls inwardly, whereas the walls are moved outwardly by the pressure in the bale chamber, when the gate opens.
EP 1 595 438 A discloses a round baler having a belt-slat conveyor extending beyond side walls of a bale chamber and running over support wheels. Since the belts initially extend straight between the support wheels, but get deflected when sufficient crop enters the bale chamber, a gap appears between the belt run and the outer edge of the side wall, into which crop may enter and create blockages.
Document “KRONE RoundPack”, printing reference Round Pack 1250/1550 (D) shows a round baler with a chain-bar conveyor, whereas at the end of the bars rolls are provided. These rolls are supported on a track behind the sidewalls of a bale chamber, whereas the bars move along the sidewall edge with a distance. Between the bars and the outer edge of the side wall a gap is provided.
From DE 4 105 078 A1 it is known, to cover the part of the bale chamber in the gate by an endless and closed bale forming element rolling along and on the circumference of the semi-circular side walls of the gate. In order to release the bale, the gate is opened with the sidewall and the endless bale forming element.
Furthermore it is ordinary practice in fixed chamber balers, to let the gate open slightly at the end of the baling process in order to achieve a higher density on the circumference as well as to achieve a bigger bale diameter. When the gate opens, a gap occurs between the gate and the frame, through which brittle crop may escape.
The problem this invention is based on is seen in the multiple gaps found in these balers, through which crop may escape or may plug, especially once the gate opens, even if it is for a few centimeters only.